Method of regulation and regulating device for an apparatus or group of apparatuses, as well as an apparatus having a regulating device

ABSTRACT

The method of regulation employs a simulation process for at least one state variable of an apparatus to be controlled and regulates the state variable. In the process, a curve of an operating characteristic having its base at an idle state value is traversed up to an operating state value. When re-regulating, the regulation process begins at the current value of the state variable. The value of the regulation variable corresponds to the idle state. This has the advantage of a defined initial point for re-regulation. A regulating device for performing the method of regulation comprises a series circuit containing an input circuit, a regulation circuit with a simulation device for regulating an apparatus as well as a control circuit for possible machines coupled to the apparatus. The simulating device is adjustable according to operating characteristics or apparatus parameters. Another regulating device fulfills the same function while employing a computer and correspondingly modified circuits.

BACKGROUND OF THE INVENTION

The present invention broadly relates to the regulation of apparatusand, more specifically, pertains to a new and improved method and devicefor regulating an apparatus or group of apparatuses and to an apparatushaving a regulating device.

The apparatus to be regulated can, in particular be arranged to processfabric edges or selvedges and can, for instance, be an electrothermalshear.

Fabric edges or selvedges are in many cases and independently of theweaving process severed or cut off in weaving. The newly formed fabricedge must be bonded.

In woven fabrics which comprise synthetic fiber components, the fabricedges or selvedges are often severed by means of a thermal or heatedshear which welds or fuses the newly formed fabric edges during thesevering process. In fabrics without a substantial synthetic fibercontent, special measures must be taken and special devices employed inorder to bond the fabric edges.

However, an exact control of the operation of this processing device inrelation to the materials employed in the woven fabric is required forboth groups.

In heretofore known devices, especially in known thermal shears, this isnot the case.

For example, one known thermal shear comprises a heated rod containing apotentiometer coupled to the rod which is pivotable in a joint or hingeand is journaled to swing or pivot in a direction extendingsubstantially transverse to the plane of the fabric length. This knownthermal shear is pressed against the initial or forward edge of a fabriclength by means of a spring. In the nearly vertical idle position, thepotentiometer feeds a current into the rod which prevents the rod fromheating too strongly or from heating at all. As the rod is deflected bythe traveling fabric length, the potentiometer feeds a current into theheated rod enabling the rod to sever the fabrics.

This thermal shear has the disadvantage that the heated rod continues tomelt the fabric with its residual heat after the cloth of fabric lengthhas ceased to move and the cutting or severing current has been switchedoff. Since the fabric length no longer moves, damage to the fabricoccurs in the region of the idle position of the only slowly coolingrod.

Another electrothermal cutting apparatus is known from the German Pat.No. 3,140,560 and comprises a circuit arrangement for regulating thesupply of current during the operating interval and during the idleinterval. The circuit arrangement automatically sets a higher currentsupply at the beginning of the operating interval and switches it offagain at the end of the operating interval. The circuit arrangement alsocomprises circuitry operating according to the phase shift controlmethod and having adjustable delay circuits and a switching deviceactuated by the drive of the machine being regulated. The time constantof the first delay device depends upon the position of a closure contactcontrolled by the processing machine. Both delay circuits conjointlywith a power control stage effect a phase shift control whose firing ortriggering angle is determined by the two delay circuits.

The magnitude of the firing or triggering angle determines the onset andthe duration of the current flow through the power control stage andthrough the cutting or severing device. The current flow or flux can beadapted to the type and thickness of the fabric to be severed as well asto the operating and idle intervals. A substantial disadvantage of thiscircuit arrangement is the very slow temperature rise at the shear orshears when switching from the idle interval to the operating interval.For rapidly operating machines this temperature rise occurs too slowly,which leads to fabric waste or scrap.

SUMMARY OF THE INVENTION

Therefore, with the foregoing in mind it is a primary object of thepresent invention to provide a new and improved method and device forregulating an apparatus as well as an apparatus regulated by the deviceand method which do not have associated with them the aforementioneddrawbacks and shortcomings of the prior art constructions.

Another and more specific object of the present invention aims atproviding a new and improved method and device for regulating anapparatus or group of apparatuses enabling the alternation between twovalues of at least one state or operating variable to be very rapidlyeffected. For instance, when switching from the idle or rest state tothe operating state, the value alternation is to be effected veryrapidly. In particular, such a regulation device is to be connected toan apparatus for cutting off or severing the fabric edges or selvedgesfrom a fabric length.

Yet a further significant object of the present invention aims atproviding a new and improved construction of a device of the characterdescribed which is relatively simple in construction and design,extremely economical to manufacture, highly reliable in operation, notreadily subject to breakdown or malfunction and requires a minimum ofmaintenance and servicing.

Now in order to implement these and still further objects of theinvention, which will become more readily apparent as the descriptionproceeds, the method of the present invention is manifested by thefeatures that it comprises the steps of tapping or extracting at leastone state or operating variable of the apparatus to be regulated fromthe apparatus to be regulated or from a control circuit of the apparatusto be regulated, conducting the tapped state or operating variable to asimulation circuit for simulating a variable of an operatingcharacteristic of the apparatus to be regulated, and conducting thesimulated value of the operating characteristic to a comparison andregulation circuit for regulating the apparatus.

The device of the present invention is manifested by the features thatit contains an input circuit, a regulation circuit connected to theinput circuit and a control circuit connected to the regulation circuit.

The apparatus of the present invention is manifested by the featuresthat it comprises an apparatus for severing or cutting off selvedges offabric lengths.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those setforth above, will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the annexed drawings wherein throughout the various figures of thedrawings there have been generally used the same reference characters todenote the same or analogous components and wherein:

FIG. 1a diagrammatically shows curves of operating characteristics ofthe operating temperature in a device according to the state of the artand according to the invention, respectively;

FIG. 1b diagrammatically shows further characteristic curves ofoperating behavior according to the invention;

FIG. 2 is a schematic circuit diagram of a first embodiment of aregulating device according to the invention; and

FIG. 3 is a schematic circuit diagram of a second embodiment of aregulating device according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Describing now the drawings, it is to be understood that to simplify theshowing of the drawings only enough of the structure of the device hasbeen illustrated therein as is needed to enable one skilled in the artto readily understand the underlying principles and concepts of thisinvention. The illustrated exemplary embodiment of the device will beseen to comprise an input circuit 210, a regulation circuit 220 and acontrol circuit 230. In the method of regulation according to theinvention momentary value of at least one state of operating variableare tapped off or extracted from the apparatus to be regulated, forinstance the voltage or the current or the power, and conducted to theregulation circuit 220. These momentary values of the state or operatingvariable are converted in the regulation circuit 220 and a preselectedcourse of variation of every operating characteristic of the apparatusis simulated in a simulating device 223 by means of the state oroperating variables. Feedback signals for the regulation of theapparatus are generated from this course of variation as well as fromapparatus parameters.

In producing each feedback signal, the tapped and converted signalcorresponding to the state or operating variable is combined withsignals corresponding to specific device properties, the so-calledapparatus parameters. It is combined, for instance, with signalscorresponding to the particular type of apparatus 100 or with machineconstants. The simulating device 223 simulates the behavior of theapparatus, i.e. the course or variation of the value of at least one ofthe operating characteristics of the apparatus in dependence of thestate variables and of the apparatus parameters. For instance, in anelectrothermal severing or shearing device one of these operatingcharacteristics can be the temperature at the cutting wire. Theparticularly rapid rise of this cutting wire temperature when theapparatus is initially set in operation occurs between the idletemperature and the operating temperature.

The simulation can, for example, be performed with precisely the powerapplied to the apparatus as a state or operating variable or with avalue exactly proportional thereto as a state or operating variable.Instead of the power, however, another parameter characteristic of theoperation of the apparatus could also be employed as a state variable.

The regulation of the course or variation of the value of the operatingcharacteristics can either be performed while taking into account thevalues of the system parameters; the alternation of the values thenproceeds according to an operating characteristic which is adjustedaccording to these values of the system parameters; it is not dependentupon a possibly prescribed or prescribeable operating characteristic; orthe course or variation of the value of the operating characteristic canoccur in dependence of a prescribed reference operating characteristici.e., a reference course of variation of such operating characteristic,wherein the practically arising actual operating characteristic iscompared with the reference operating characteristic.

According to this comparison, respectively according to the deviation ofthe actual values from the reference operating characteristic, thevalues of the system parameters are readjusted or regulated such thatthe course or variation of the values of the operating characteristicsproceeds according to the reference operating characteristic. In thismanner it is possible to maintain approximately the same run-up timeunder any load and independent of the number of apparatuses.

The selection of a considerably higher heat-up operating temperature forregulation than the actual operating temperature is of basic importancefor this method of regulation with, for instance, the temperature at thecutting wire as one of the operating characteristics. In this manner, aconsiderably steeper or very high slope branch or region of thecharacteristic curve, for instance a logarithmic function to the base e,i.e. a natural log function, which leads to the operative state of theapparatus, can be selected and thereby a correspondingly shorter timeinterval for the heating-up process to the actual operating temperatureobtained.

Upon attaining the operating temperature, this temperature is maintainedconstant by the regulation device, i.e. the characteristic curve isessentially extended or continued at this point by a straight(horizontal) branch. This eliminates the asymptotic approach to theoperating temperature which requires a great deal of time. The overshootdue to technical conditions generally remains in negligible orders ofmagnitude. Furthermore, for every re-regulation process, whether formaintaining the operating temperature constant or after an interruptionof operation and partial cooling off of the electrothermal cuttingdevice, regulation in this method of regulation begins at the finaltemperature corresponding to this cooling-off, but the heating-upcurrent imposed upon the apparatus has a value corresponding to thestate in which the characteristic curve runs through the base point,i.e. the idle temperature point, as will be understood from FIGS. 1a and1b.

This method of regulation can be more precisely and more rapidlyexecuted than other methods. This is especially true because the sameunambiguously defined run-up curve is always employed.

The feedback signal is supplied to a comparison and regulation circuitwhich controls the apparatus and other circuits, for instance a controlcircuit.

The apparatus to be regulated can, as mentioned, be an electrothermalsevering or cutting apparatus 100 for woven material. Such severingapparatuses or selvedge cutters are preferably mounted on the weavingmachine at the edges of a fabric length. They sever the fabric edges orselvedges from the traveling fabric length. The thus newly createdfabric edges are simultaneously bonded by the severing process, inparticular they are welded or fused when the fabric contains syntheticfibers.

One or more electrothermal severing apparatuses 100 can be connected toa regulating device 200 for controlling and regulating the power supplyand the stages of operation.

A roller shear with a bonding device, or similar apparatus, can beprovided for producing a durable fabric edge instead of electrothermalseverance or cutting-off.

The regulating device 200 operates according to the initially describedmethod of regulation according to the invention and comprises the seriescircuit including the input circuit 210, the regulation circuit 220 andthe control circuit 230.

The input circuit 210 comprises an adjustable potentiometer 211 for theidle state temperature and an adjustable potentiometer 212 for theoperating state temperature, both of which are connected to a switch orswitching means 213 for switching from one operating state to the other.A test push button 214 is also connected to the switch 213 to throw orcommute it between the idle and the operating state positions whenpressed and is also operated for checking or monitoring a suitabledisplay lamp 218. A rectifier 216 is connected to an operating signalentry circuit 215 for an operating signal of a weaving machine or thelike (since the processing device, i.e. the selvedge cutter or shear, isonly to be operated when the machine is in operation). An isolatingcircuit 217 for the galvanic isolation of the regulating device 200 frommains or line voltage, e.g. by means of an opto-coupler, is connected tothe rectifier 216 and also to the switch 213.

The output 213A of this switch 213 forms or defines the output of theinput circuit 210 and is connected to a comparator circuit 221 on aninput side 220A of the regulation circuit 220. The comparison circuit221 is also connected to an output of a simulation device 223 of theregulation circuit 220 and carries out a comparison between thereference values and the actual values supplied by these two inputsignals. A PI regulator 222 connected to the comparator circuit 221trims or adjusts the result of the comparison between the referencevalue and the actual value to zero in the regulating circuit branch. Aphase-shift control circuit 224 is connected in series with this PIregulator or controller 222 and controls the phase-shift angle independence of the regulator output voltage. A transformer 225 whosesecondary side is connected to the apparatus 100, for instance at leastone electrothermal shear, is also connected to the phase-shift controlcircuit 224.

Instead of a PI regulator or controller, a P, PD or PID controller orregulator cam also be employed. It is also possible to arrange a stateregulator or controller as a P circuit, that is a proportional circuit,in a feedback connection, that is in the connection an operatingcharacteristic regulating circuit 223.2 and the comparator circuit 221.A state controller or regulator hierarchy can also be provided whenregulating several state variables.

A current converter 226 for tapping off or detecting the regulatedoutput variable, i.e. the current, is provided between the transformer225 and the selvedge cutter or shear. This current is represented orsimulated as a voltage value or potential drop across a resistance andis converted into direct current in a rectifier 227. The direct currentis then squared in a square-law transfer circuit 228 in order to obtainan input variable corresponding to the power for the simulation circuitor device 223.

If the apparatus to be regulated represents a constant load to theregulation circuit, then the current is regulated as the outputvariable. It is, however, also possible, according to the individualcase, to regulate the voltage. This is especially true when severalapparatuses to be regulated are connected in parallel to one another.

The simulating circuit or device 223 comprises an input circuit 223.1 ofinput means 223.1, 223.2 for inputting a predetermined system parametersdependent upon the type of apparatus 100 to be regulated. This input caneither be manual or automatic and governed by the construction of theapparatus. Furthermore, a circuit 223.2 of the input means 223.1, 223.2for altering the amplification factor in conformity with the type ofshear is provided in the simulation circuit or device 223 and iscontrolled by the input circuit 223.1. An operating characteristiccircuit 223.3 is connected with the input circuit 223.1 and with thealteration circuit 223.2.

The operating characteristic circuit 223.3 determines the preselectedoperating characteristic curve branch for the temperature rise from theidle state temperature to the operating state temperature in dependenceof the type of processing device or shear and in dependence of itsregulation parameter correspondingly transformed or converted by thecircuit 223.2 as well. The operating characteristic circuit 223.3correspondingly transmits a continuous feedback signal as its output tothe comparator circuit 221. In the present case, the temperaturebehavior is simulated in dependence of the time of the processingapparatus in this simulation circuit 223 and there is generated acorresponding feedback signal.

In one embodiment, besides taking into account the type of processingapparatus, parameters which are determined by the mounting on theprocessing machine, for instance the weaving machine, can be input intothe simulation device 223. This can, for instance, be accomplished by amodified circuit 223.2.

The circuit 223.2 for altering the amplification factor or gain can alsobe connected at another point of the regulation device 200, for instanceahead of the switch 213.

The regulation circuit 220 is designed or dimensioned such that the sameoperating characteristic curve branch is always traversed in everyheating-up regulation process. After an interruption of operation and apartial cooling off of the electrothermal cutting or shearing device,the regulation begins again at the final temperature corresponding tothis degree of cooling off at the higher value of heating up currentcorresponding to the initial or base point of the operatingcharacteristic curve, i.e. the idle state temperature, as can best beunderstood with reference to FIG. 1b.

The control circuit 230 is connected both to the output of the PIregulator or controller 222 and to the output of the rectifier 227. ThePI controller or regulator 222 is connected to one input 232.3 of an ANDgate 232 whose other input 232.1 is connected to an inverter 231. Theinverter 231 is connected to the rectifier 227. The AND gate 232controls via its output 232.3 an output relay 233 for controlling amachine, for instance a weaving machine.

The control circuit 230 transmits a termination-ofoperation signal tothe processing machine only when the apparatus 100 has been damaged.During current-free intervals generated by the regulation circuit, notermination-ofoperation-signal is generated.

In another embodiment of the regulation device according to theinvention, an input circuit 310 for inputting the values for the idlestate temperature, the operating state temperature, the type ofapparatus to be regulated and the functions for calibrating and testingor for displaying these values or for both inputting and displayingthese values is connected to a computer or control processor 320. Thecomputer 320 is also connected to an entry circuit 350 for receiving orinputting an operating signal, for instance from a weaving machine atthe start of the weaving operation. A control circuit 330 which suppliesthe apparatus to be regulated with power and which derives signals ofone or more of the apparatus' state variables and processes them is alsoconnected to the computer 320.

In addition to the means for tapping or detecting and processing thesignals for at least one of the state variables, for instance thecurrent converter 332 and the rectifier 333 and so forth the controlcircuit 330 also comprises an electronic power switch 331. The powerswitch 331 and the rectifier 333 are connected to the computer 320.Signals flow from the computer to the electronic power switch 331,respectively from the rectifier 333 to the computer 320. The currentconverter 332 is arranged ahead of the apparatus 100 to be regulated inthe conductor or lead coming from the electronic power switch 331. Thelatter adjusts the width of the pulses for supplying energy to theapparatus on the basis of signals coming from the computer 320 in themanner of a pulse-width controller. Furthermore, an output circuit 340is connected to the computer 320 and comprises means for transmittingcontrol signals to a machine linked to or connected in series with theapparatus, for instance a weaving machine, as best will be seen in FIG.3.

The apparatus 100 to be regulated can, in particular, be a heated wireshear device or a roller shear device having means for thermally bondingfabric edges.

While there are shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto, but may be otherwise variously embodied and practicedwithin the scope of the following claim. Accordingly,

What we claim is:
 1. A method of regulating an apparatus or group ofapparatuses, comprising the steps of:tapping at least one state variableof the apparatus to be regulated from the apparatus to be regulated;conducting said at least one tapped state variable to a simulationcircuit for simulating an operating characteristic of the apparatusaccording to a preselected course of variation of such operatingcharacteristic and thereby generating simulated values of such operatingcharacteristic and which simulated values are related to said at leastone tapped state variable; conducting said simulated values of saidoperating characteristic to a comparison and regulation circuit andthereby regulating the apparatus to be regulated; selecting as saidpreselected course of variation a course of variation having apredetermined branch which leads to an operative state of the apparatusto be regulated; and selecting as said predetermined branch a branch ofa logarithmic function to the base e and which branch has a very highslope.
 2. A regulating device for regulating an apparatus or group ofapparatuses, comprising:an input circuit; a regulation circuit connectedto said input circuit; said apparatus regulated by the regulating devicebeing operatively associated with a machine; a control circuit connectedto said regulation circuit and controlling the operation of saidmachine; said regulation circuit containing on its input side acomparator circuit which is connected to an output of said inputcircuit; said comparator circuit comparing reference values receivedfrom said input circuit and simulated values of an operatingcharacteristic related in a predetermined relationship to momentaryvalues of at least one state variable of said apparatus regulated by theregulating device; said regulation circuit further containing: a PIregulator series connected with said comparator circuit; a phase-shiftcontrol circuit series connected with said PI regulator; a transformerseries connected with said phase-shift control circuit and operativelyconnected with said apparatus regulated by the regulating device; acurrent converter for measuring current and interconnecting saidtransformer and said apparatus regulated by the regulating device; saidcurrent converter being mounted at said apparatus regulated by theregulating device; a rectifier series connected with said currentconverter; a square-law transfer circuit series connected with saidrectifier; a simulation circuit series connected with said square-lawtransfer circuit; said operating characteristic of said apparatus beingvariable according to a preselectable course of variation; saidsimulation circuit taking into account said preselected course ofvariation of said operating characteristic; and said comparator circuiton said input side of said regulation circuit being connected in serieswith said simulation circuit.
 3. The regulating device as defined inclaim 2, wherein:said simulation circuit in said regulation circuitcontains input means for inputting at least one system parameter relatedto said apparatus regulated by the regulating device; said simulationcircuit further containing an operating characteristic circuit seriesconnected with said input means; said operating characteristic circuit,in response to signals infed by said input means and constitutingmomentary values related to at least one state variable of the apparatusregulated by the regulating device, generating simulated values of saidoperating characteristic according to said preselected course ofvariation of said operating characteristic of said apparatus regulatedby the regulating device; and said simulation circuit feeding to saidcomparator circuit said simulated values related to said predeterminedoperating characteristic and said at least one system parameter of saidapparatus regulated by the regulating device.
 4. The regulating deviceas defined in claim 3, wherein:said preselected course of variation ofsaid operating characteristic constitutes a time constant.
 5. Aregulating device for regulating an apparatus or group of apparatuses,comprising:an input circuit; a regulation circuit connected to saidinput circuit; said apparatus regulated by the regulating device beingoperatively associated with a machine; a control circuit connected tosaid regulation circuit and controlling the operation of said machine;said regulation circuit contains a rectifier and a PI regulator; saidcontrol circuit containing an inverter series connected with saidrectifier in said regulation circuit; said control circuit furthercontaining an AND gate having two inputs and an output; one of said twoinputs of said AND gate being connected to said inverter; a further oneof said two inputs of the AND gate being series connected to said PIregulator;
 6. A regulation device for regulating an apparatus or groupof apparatuses, comprising:a computer; an input circuit operativelyconnected to said computer; the apparatus regulated by the regulatingdevice being associated with a machine; an entry circuit connected tosaid computer and generating an operating signal for said machine withwhich said apparatus is associated; a control circuit interconnectingthe apparatus regulated by the regulating device and said computer; saidcontrol circuit supplying and metering power to said apparatus; saidcontrol circuit receiving and processing momentary values of at leastone state variable of said apparatus and inputting processed valuesrelated to such momentary values into the computer; an output circuitconnected to said computer and controlling the operation of saidmachine; said control circuit containing an electronic power switchconnected to said computer; said control circuit further containingpulse-width control means controlling the power fed to said apparatusregulated by the regulating device; and said electronic power switch ofsaid control circuit being adjusted by said computer for maximum pulsewidth.
 7. An apparatus regulated by a regulating device containing aninput circuit which includes at least one adjusting element foradjustment of at least one reference value related to an operatingcharacteristic of the apparatus and a regulation circuit includingsimulation means receiving momentary values of at least one statevariable from said apparatus and generating therefrom simulated valuesaccording to a preselected course of variation of said operatingcharacteristic for comparison with said at least one reference value insaid regulation circuit; and comprising:an apparatus for severingselvedges of fabric lengths and constituting said apparatus regulated bythe regulating device.
 8. The apparatus as defined in claim 7,wherein:said apparatus comprises a thermal wire shear device.
 9. Theapparatus as defined in claim 7, wherein:said apparatus comprises amechanical shear device having means for bonding severed edges of fabriclengths.
 10. The apparatus as defined in claim 9, wherein:saidmechanical shear device comprises a roller shear.
 11. A regulatingdevice for regulating an apparatus or group of apparatuses,comprising:an input circuit; a regulation circuit connected to saidinput circuit; said apparatus regulated by the regulating device beingoperatively associated with a machine; a control circuit connected tosaid regulation circuit and controlling the operation of said machine;the apparatus regulated by the regulating device being capable ofassuming a predetermined number of operating states; said input circuitcontaining a predetermined number of adjusting elements for adjustingrelated reference values each of which is associated with one of saidpredetermined number of operating states of said apparatus regulated bythe regulating device; said input circuit further containing switchingmeans switchable between a predetermined number of switching states eachof which is associated with a related one of said reference valuesassociated with said predetermined number of operating states of saidapparatus regulated by the regulating device; said predetermined numberof adjusting elements being connected to said switching means forswitching said switching means between said predetermined number ofswitching states; said input circuit further containing an manuallyoperable test push button switch; said input circuit further containinga galvanically isolated entry circuit operatively associated with saidmachine with which said apparatus is operatively associated; saidswitching means being connected with said manually operable test pushbutton switch and said galvanically isolated entry circuit; and saidswitching means containing an output connected with said regulationcircuit on an input side thereof.
 12. The regulating device as definedin claim 11, wherein:said apparatus regulated by the regulating deviceconstitutes a heating apparatus; said predetermined number of operatingstates of said heating apparatus constitute two temperature states ofsaid heating apparatus; said two temperature states of said heatingapparatus constituting an idle temperature state and an operativetemperature state of said heating apparatus; and said predeterminednumber of adjusting elements constituting two adjusting elements foradjusting reference values respectively related to said idle temperaturestate and said operative temperature state of said heating apparatus.